If you are already at Catalina check out Catalina Divers Supply about
1/2 way to the end of the green pier.

Good boad good people been there same location since the stone age so to
speak.

Another good one on island is Scuba Luv They also carry Nitrox.

Mainland i'd sap Pacific Salty Adventures (Boat) Runs with Pacific
Wilderness Dive Shop. (Out of San Pedro) (SP)

Good crew and Great bunch of guys.

Try to get Fred their main Tech guy ya can't go wrong with this bunch.

Safe Diving.

L8R